KUDU-2671 implement decoding of RowOperationsPB in Java client

This patch implements decoding of range partitioning information
out of RowOperationsPB.  A few tests added as well to cover the
new functionality.

In the context of supporting custom hash schemas per range in the
Kudu Java client, a few follow-up changelists need the newly introduced
functionality.

Change-Id: I4f69f89f6b9e47d79b83c2109d85a95288bec380
Reviewed-on: http://gerrit.cloudera.org:8080/18494
Reviewed-by: Attila Bukor <abukor@apache.org>
Reviewed-by: Mahesh Reddy <mreddy@cloudera.com>
Tested-by: Alexey Serbin <alexey@apache.org>
4 files changed